Dynamic response analysis of the process of the utility shield tunnel under-passing the operating subway tunnel

Abstract

In order to analyze the interaction between the operating subway tunnel and the utility tunnel under construction during the utility tunnel under-passing the subway tunnel, an operating tunnel-stratum-utility shield tunnel coupled dynamic calculation model is established taking the utility tunnel under construction under-passing the Guangzhou-Foshan line subway project as an example. And the interaction between the existing tunnel and utility tunnel was studied. The results show that the amplitude change of the vertical displacement, acceleration and additional vertical stress are most influenced by the under-passing shield tunnel when the train operating on one line, and the max changes are 0.01 mm, 0.03m/s2 and 1.5kPa, respectively. The vertical displacement and acceleration response generated by the train operation during the excavation of the new tunnel can be neglected, but the vertical additional stress will have the max change of 2.1kPa. The closer the distance between the train load to the new and old tunnel structures are, the greater the displacement, acceleration and additional stresses of the new and old tunnel structures are when the trains are running in different lines. Structural safety calculations show that the old and new tunnel structures are safe during the utility shield tunnel under-passing. The study can provide useful reference for the construction and operation of similar tunnels.